I tried to explain (and I imagine you other non-French speakers are equally at a loss, and for that, I apologize) but explaining these sorts of things never means actually being able to impart why the thing is funny. Or not.
Mom, I'm sorry. You are so not going to get this one.
The whole premise is making fun of horribly dubbed American soaps on French TV. The whole joke is how the actors who do the ridiculously bad dubbing get distracted. Believe me, it's funny in French, but almost because it is so bad. It's the kind of humor that makes you groan. The kind where you are almost mad at yourself for laughing.
Okay, I'm totally laughing over here just remembering it.
God, it's dumb. But it's so funny.